Qt appears on both legitimate first-generation output and downstream re-save flows — context (the other tool on the same document) is what flips the signal.
Back to all statisticsForensic verdictBased on 365 appearances across the HTPBE? corpus.
Corpus profile
Qt’s PDF backend ships with the Qt application framework and is used by a wide range of desktop apps that emit PDFs. It is also used by some PDF-editing utilities.
Qt as Producer is legitimate inside many desktop apps. The contextual signal is when Qt appears as the latest Producer on a document whose Creator points to an institutional generator — that producer/creator mismatch indicates a desktop-app re-save.
Role in the workflow
Every PDF carries a Creator (the application that produced the original document) and a Producer (the engine that wrote the PDF). The same tool can appear in either slot, with very different modification profiles.
Name fingerprints
Different version strings and spellings observed for Qt in the wild. All are merged into the same canonical profile.
Why variants matter
The same tool publishes itself under 7 different metadata strings — version bumps, locale tags, build IDs. We canonicalize them so the corpus reflects one identity, not noise.
Distributions
The PDF versions Qt writes when acting as Producer, and the other tools that appear in the same documents.
Most output is PDF 1.4 (99% of files where Qt is the Producer).
Related profiles
Other tools that frequently share metadata with Qt in the same documents. Each card links to its own forensic profile.
Long tail
Smaller cuts of the Qt corpus — useful context, but treat each row as a single data point rather than a strong signal.
PDFs carrying at least one digital signature
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